Electric switch



July 20, 1926. 1,593,434

J. R. CARLSON ELECTRI C SWITCH Filed Nov. 10, 1922 MEL INVENTOR JOHFINNES R. CQRLSOH [fly/M W A TTORNE Y3 Patented July 20, 1926.

UNITED STATES PATENT OFFICE.

J'CHANNES R. CARLSON, OF'HARTFORD, CONNECTICUT, ASSIGNOR TO THE ARROW ELECTRIC COMPANY, OF HARTFORD, NECTICUT.

CONNECTICUT, A CORPORATION OF CON- ELECTRIC SWITCH.

Application filed November 10, 1922. Serial No. 600,138.

I as illustrated in the accompanying drawing,

in which- I Fig. 1 is a plan view of a switch in which my invention is embodied in one form, the switch blades and their operating mechanism being removed;

Fig. 2 is a section on-the line 2.-2, Fig. 1;

Fig. 3 is an end elevation of the switch;- gig. 4 is a section on the line 4-4, Fig. 1; an

Fig. 5 is a detached perspective of the polechanging contacts and connections drawn to a larger scale.

In the form illustrated, the switch comprises an insulating body 6 of cup shape to accommodate a switch mechanism of any suitable type, such for instance as that shown in patent to Harrington 1,514,458 November 4, 1924. At the opposite ends of the switch chamber 7, the end walls of the cup-shaped body are provided with depressed ledges 8, 9, 10 and 11. Above each of the ledges is arranged a terminal plate 12 tapped to receive a binding screw 13 and having an outwardly extending switch contact 14 offset at right angles thereto. Each plate is also tapped to receive se- 5 curing screws 15, which pass through the projecting end shoulder 16 of the base and serve to hold each terminal in position. It will be noted that the contact pieces 12 atdiagonally opposite corners of the switch body are of identical shape. But two sets of dies are therefore necessary for their formation.

Arranged beneath each plate 12, and spaced therefrom at one end of the switch 5 chamber by interposed metal washers 17,

(Fig. 4), is a second contact plate 18 having a downwardly extending leg 19 confined in a narrow channel 20 in the end wall of the porcelain, and having at its lower end an offset, inwardly-projecting contact 21 arranged in the same vertical plane as the upper contact 14. This plate is also pierced, in register with the plate 12, to permit the securing screws 15 to pass therethrough, so that both are held in position on the base by the same means. It is also pierced to permit the binding screw 13 to pass down freely therethrough-only ,theupper plate 12 being tapped toafford a threaded engagement therewith. At this end of the switch chamber, the upper and lower contacts '14 and 21 of each pair are electrically connected, and of the same polarity.

At the opposite end of the chamber, however, the upper and lower terminal plates 12 and 18 are spaced apart, not by metal washers 17, but by sheets of insulation 22. More-.

over the holes in the lower plates 18 through which the securing and binding screws pass are enlarged and lined with insulating bushings 23 to prevent electrical contact with the screws. Associated with the terminals are pole-changing straps 24 and 25 adapted to span the end of the receptacle transversely, and to afford a connection between the upper contact 14 at one side of the receptacle-and the lower contact 21 on the other side of the receptacle, and vice versa. The straps are of the same construction, but are reversed in position and are so offset, intermediate their ends, that one passes outside the end boss 26 of the receptacle body and rests upon the ledge 27, while the other is arranged on the opposite side of the boss '26 and rests upon the ledge 28. These ledges 27 and 28 he substantially in the plane of the ledges 10 and 11, and in effect form continuations thereof. In assembled position, the straps underlie and are directly engaged beneath the terminal plates 12 ofthe upper contacts 14 and pass transversely of the receptacle end and on opposite sides of the boss 26 beneath the extended legs 29 and 30 of the two insulating sheets 22, and are engaged at their opposite ends beneath the terminal plates 18 of the lower contacts 21'. The obvious result of the arrangement is to reverse the polarity of the upper and lower contacts of each of the contact pairs at this end of the switch.

This pole-changing phenomenon being in itself well known in the art, .its purpose need not be explained, since the invention resides in structure rather than in novelty of technical result.

The present construction has the great advantage of simplicity of manufacture and assembly. The contacts proper are of like construction at both ends of the switch, except that at the pole-changing end, the holes in the base plate 18 of the low contacts 21 are punched larger to receive the nsulating bushings 23. The contact supporting ledges 89 and 10-11 at opposite ends of the switch chamber, may lie in the same plane, since the washers 17 are of the same thickness as the combined thickness of the insulating strips 22 and pole-changing straps 24, and thus serve to maintain the vertical spacing of the upper and lower contacts 14 and 21 uniform at opposite ends of the switch. The same insulating base may therefore be used for either the usual double-pole switch or for a pole-changing switch. In fact the switch as shown ma be readily converted into an ordinary ouble-pole' switch, if washers 17 be used at both ends of the switch, (the insulating sheets and polechanging straps being of course omitted), or the washers 17 may be entirely omitted and the base plates 12 and 18 may be directly juxtaposed-if the throw of the switch bar is such as to make this practicable.

Various modifications in detail of construction and arrangement of the parts shown will readily occur to those dealing with the problem, without departing, however, from what I claim as my invention.

I claim- 1. In a pple-chan ing switch, a cupshaped insu ating bo y having at one end a pair of depressed ledges, pairs of upper and lower contacts having base plates arranged above each of said ledges,- but insulated from each other, pole-changing straps extending between the upper contact base plate on one ledge and the lower conname to this specification.

tact base plate on the other ledge, together with means-engaging the upper base plate depressed ledges lyin on each ledge to hold the and in engagement with sai straps.

2. In a ole-charging switch, a cupshaped insu ating y aving at one end a boss and de ressed ledge supports surrounding said ss, contact base plates arranged on said ledge support on opposite sides of said boss transversely of the switch, and pole-changing straps arranged on said ledge support on opposite sides of the boss longitudinally of said body and serving to connect certain of said base plates on one side of the boss with certain of the base plates on the opposite side of said boss.

3. In a pole-changin switch, a cupshaped insulating bo y having at one end a-pair of depressed ledges, airs of upper and lower contacts having ase plates arranged above each of said ledges, but inarts assembled d pole-changing sulated from each other, pole-changing straps extending between the upper contact base plate on one ledge and the lower contact base plate on'the other led together with means passing through said ilgaseplates and straps and engaging the upper base plate on each ledge to hold the parts assembled and in engagement with said polechanging straps.

4. In an electric switch, a cup-shaped insulating base having at its opposite ends in substantially the same plane, upper an lower switch contact plates on each of said ledges, pole-changing and insulating means spacing apart certain of said plates at one end of said switch, and metal washers spacing apart the plates at the opposite end of the switch to maintain their associated contacts in the' same planes.

In testimony whereof I have signed my J OHAN'NES R. GARLSON. 

